In the field of dental hygiene, it is known that it is advantageous to use a soft-bristle toothbrush for regular home-cleaning regimens. This is particularly true, from the specialized view of the field of periodontistry. That area of dentistry is principally concerned with the physiology and pathology of the gums and other "soft-tissue" of the tooth-bearing region of the mouth, vis-a-vis the teeth themselves and their associated skeletal regions. More particularly, periodontistry is directed toward preventing and correcting the diverse effects of plaque-causing bacteria in the gingival sulcus area under the gum flap which covers the base of the teeth.
In the daily home-practice of oral hygiene, periodontists strongly favor the use of toothbrushes having soft bristles. The reasons for this are to provide a brush which is sufficiently flexible to massage thoroughly the soft tissues of the mouth, to stimulate blood circulation, and to disorganize bacteria; all without causing undue trauma to the oral tissues. Further, the straight bristles normally used in a conventional brush, are not effective to scour comfortably under the gum flap.
Currently, the bristles in toothbrushes are almost always made from thermo-plastic materials. Inherently, these are easily deformed. Soft bristles, being inherently even more supple and susceptible to bending than "hard" bristles which are thicker and/or made from material which is more rigid structurally, are not useful for any reasonable period of time in the manner which periodontists particularly seek. Such bristles individually spread and bend over and become fixed more or less permanently in a multitude of directions, rather than staying aligned, more or less. Thus, the bristles do not present a coordinated mass of soft bristles to the brushed area. This can render the brush unusable, particularly over any considerable length of time, and even hazardous to the soft tissues in the mouth.
The long, soft, bristles in the presently available designs are, inherently, individually, structurally weak, and readily collapse under pressure. For this reason, brushes are made available in the "medium" and "hard" bristle types so they will stand up better under the pressure of brushing. Yet these are counter-productive because the stiffer bristles have a greater tendency to injure the soft tissues. This tendency to injury increases as the bristles spread with use.
From the foregoing, it may be seen that:
All present brushes become permanently deformed with use and increasingly become unsatisfactory for use.
The basic shape of the present bristle design does not lend itself to reaching the vital sulcus area under the gum flaps.
The soft bristles rapidly become deformed with repeated use and do not present a resilient coordinated mass of soft bristles for brushing action.
The "medium" and "hard" brushes provide increased resilience, when new, but soon take a self-defeating spreading set.
Further, it is the natural characteristic of wet thermoplastic and other types of bristles to take a permanent "set" when repeatedly forced into disarray by the brushing action. As is well known, this disarray becomes a permanent shape of the brush, and thereby renders it hazardous to use. However, this characteristic of taking a "set" while wet can be controlled, and the resulting, permanent shape can be trained into an improved and highly advantageous arrangement by the use of a training clamp.
Further, because the bristles are soft, they will be bent into undesirable disarray if they are forced into a permanently arranged spring clamp. The clamp must be removably affixed so that it may be repeatedly applied and re-applied without disturbing the bristles into a non-perpendicular disarray and causing them to take the wrong "set".
All of the above establishes a need to form the bristles of a soft bristle toothbrush in a manner to substantially increase the effective resilience of the soft bristles, to eliminate the need for the "medium" and "hard" brushes; and to at the same time, produce a maintainable, coordinated mass of soft bristles, so formed that the sulcus area is properly addressed, and all surfaces are comfortably and effectively scoured.
A variety of proposals have been made for straightening brush bristles after use. Some of them contemplate pressing to a limited degree on the free ends of the outer bristles so as to cause them to deflect inwards, so as to make the group of bristles form a uniform mass without edge fraying. In this connection, reference is made U.S. Pat. Nos. 271,814; No. 637,522; No. 1,444,677; No. 3,120,019; and No. 3,995,743. However, even these prior art teachings do not produce results desired by periodontists and other such specialists in oral hygiene since, even when practiced with soft bristle brushes, the effect at best is merely to reduce edge-fraying. Consequently, the prior art devices provide no greater remedial effect than is available in any soft toothbrush, even when brand new and unfrayed.
Accordingly, it is the object of this invention to provide a means whereby the natural weakness of the wet, soft, bristles to splay out with use can be controlled, and the wet bristles trained to deform in an advantageous shape. The repeated act of clamping the wet brush tightly in the approximate 70% of length area while it is not in use, together with the splaying effect of the brushing action, gradually produces a brushing "flare" of soft bristles, supported by a structural wedge of soft bristles. The wet condition, the tight clamping and the bending effect of the brushing action are all three essential to the forming of the structurally supported flare.
Accordingly, it is an object of this invention to provide a means for forming soft bristles into close juxtaposition in a unique, crucial region proximal their free ends with the free ends of said bristles flared outward with respect to the region in which they are closely juxtaposed.
Still another object of this invention is to enhance the resiliency of the tooth-contacting portion of the bristles by shape and juxtaposition.
Another object is to provide a means for compressing a toothbrush such that the bristles are bent at a crucial point, and the ends are trained into a coordinated flare of soft bristles by the repeated action of brushing and clamping when wet.
Still another object of this invention is to provide a means to attain a thin resilient edge of soft bristles along the edge of the flare. Brushing with the flare against its new, assumed shape, provides a soft, resilient, thin mass of bristles that comfortably scours beneath the gum flaps. This "brushing edge" is a new concept and provides advantages not otherwise attainable.
Another object of this invention is to provide a means to reform the bristles of a toothbrush after each use into a unique coordinated mass of soft bristles.
Another object of this invention is to form the bristles of the toothbrush such that the free ends of said bristles above a crucial pressure area will be flared outward, by repeated brushing action, with respect to the lower region in which they are closely juxtaposed.
Another object of the invention is to provide a means for forming the bristles of a toothbrush in which the lower portion of bristles below a crucial bending and pressure area are formed into a wedge-like shape which converges at the pressure point.
Another object of this invention is to identify the location of the crucial pressure area in relation to the length of the bristles, above which point the flare and supporting wedge are not formed, and below which crucial area the application of a line of compression causes the bent bristles to splay outward instead of bending inward on themselves.
Another object of the invention is to establish the bristles of a dental appliance into a shape that effectively eliminates the need for a "medium" or "hard" brush.
Still another object of this invention is to provide such apparatus in a form which is removably affixable after each use.
Another object is to apply all of the above to the training of any soft bristle brush whereby an upper, flared, coordinated mass of brush ends is supported by a trained, wedge-like, formation of the coordinated lower mass of bristles so that brushing pressure causes the lower portion of the bristles to bend inward towards each other to gain increased resilient support, rather than to splay outward in individual weakness as in present cases.